Power transmission mechanism



March 11, 1952 G. H. AMONSEN 2,539,032

POWER TRANSMISSION MECHANISM Filed Feb. 26, 1949 4 Sheets-Sheet l March 11, 1952 G. H. AMONSEN 2,589,032

POWER TRANSMISSION MECHANISM Filed Feb. 26, 1949 4 Sheets-Sheet z March 11, 1952 G. H. AMONSEN 2,589,032

POWER TRANSMISSION MECHANISM Filed Feb. 26, 1949 4 Sheets-Sheet 3 y T7 J Jaye/2Z0) 620192915. 1427201221 92 3y MAZkr/ZW /WM/ March 11, 1952 G. H. AMONSEN 2,589,032

POWER TRANSMISSION MECHANISM Filed Feb. 26, 1949 4 Sheets-Sheet 4 WWW Patented Mar. 11, 1952 UNITED STATES PATENT OFFICE" POWER TRANSMISSION MECHANISM George H. Amonsen, Minneapolis, Minn. Application February 26, 1949, Serial No. 78,647 (01. 74 220) 14 Claims.

My present invention relates to automatically reversing power transmission mechanism for use in driving commercial washing machines, churns, or the like, where a periodic automatic reversal of motion is required.

An important object of my invention is the provision of such a mechanism which utilizes the driving belts and pulleys associated therewith as cooperating clutching elements.

Another, objectjof my invention is the provision of means whereby a device driven through my novel transmission may be selectively driven in either forward or reversed directions or may be automatically driven alternately in opposite directions.

'A further object of my invention is the provision of such a mechanism, which is simple and rugged in construction, inexpensive to produce, and efficient and durable in use.

The above and still further objects'and advantages willbecome apparent from the following specification, attached drawings and appended claims.

' R eferringtothe drawings in which like char-.

a cters indicate like parts throughout the several views:

gf'iggl is a view in plan with some parts being broken away, showing a preferred embodiment of my. novel transmission mechanism operatively associated with a driving motor and connections, whereby to drive a power operated device, not h wn;

Fig. a view in front elevation, some parts being brokenewvay;v

partly in section, taken-substantially on the line 7 of Fig. and

Fig. 8 is an enlarged fragmentary detail in section, taken on the line 8-8 of Fig. 5.

5; Referring more particularly to the structure of Figs. i to 4, inclusive, the numeral I indicates abase to which is secured a bearing bracket 2. Oneend of a primary shaft 3 is journalledfor rotation in the bearing bracket 2 through the medium of anti-friction bearings 4; and adjacent its other end the shaft 3 passes through and is journalled in bearing bosses 5 of a gear box 6, which in turn is secured fast to the base I. primary shaft 3 is adapted to be driven by a motor 1 having a shaft 8 to which is rigidly secured a pulley 9. A belt Ill runs over the pulley 9 and another pulley l l fast on the primary shaft 3 adjacent the gear box 6 (see Figs. 1 and 2).

A pair of axially=spaced expansion pulleys l2 and I3 are mounted on the primary shaft.3 for rotation therewith and comprise axially stationarypulley flanges l4 and I5 and axially movable pulley flanges l6 and Il, respectively. The pulley flanges [4 to ll, inclusive, are provided with sloping faces adapted to engage the opposite sides of a pair of V belts for a purpose whichwill hereinafter be described. The pulley flange l3 isprovided with a diametrically-reduced hub portion l8 which is secured to the primary shaft 3 by means of a pin l9. The pulley flange I2 is likewise provided with a diametrically-reduced hub portion 20 and is adjustably secured to the shaft 3 by means of a key 2| and a set screw22 of their respective stationary pulley flanges ll and I5. The hub 23 is free for axial sliding movements on the primary shaft 3 but is held against rotation with respect thereto by means of a sliding key 21. A collar 3a is pinned or otherwise secured to the extreme end of the primary shaft 3and cooperates with the hub l3 and the bearings 4 in the bracket 2 to prevent axial move--- ments of the shaft 3.

A pair of pulleys 28 and 29 are mounted fast on a pair of diametrically-spaced shafts 30 and 3!, respectively. These shafts are journalled in bear: ings 32 on a suitable support 33, which is bolted orotherwise secured to the base I in spaced relation to the primary shaft 3. It will be seen,

particularly by reference to Fig. 1, that the pulleys 28 and 29 are in cooperative alignment with the expansion pulleys l2 and I3, respectively. The expansion pulley l2 and pulley 28 are connected by an endless belt 34, and the expansion pulley l3 and pulley 29 are similarly connected by an endless belt 35. The belts 34 and 35 are preferably of the type commonly known as v The 3 belts and may be made from leather, rubber impregnated fiber, or the like. The belts 34 and 35 are of such length, and the distances between the expansion pulleys I2 and H3 and their respective cooperating other pulleys 28 and 29 are such that, when either of the expansion pulleys is in an axially-expanded condition, the belt running thereover will not be engaged by the expansion pulley flanges and will be allowed to idle or run freely over its associated expansion. pulley. However, when either expansion pulley is moved to its axially contracted position, the belt running thereover will be engaged for frictional driv-- ing movements by the expansion pulley flanges associated therewith.

A spur gear 36 fast on the shaft 38 has meshing engagement with a similar gear 3! fast on. the shaft 3| whereby to cause the pulleys 28 and 29 to rotate in opposite directions. The shaft" 3| is.

herein shown as being a power output shaft and is provided with a sprocket 38 over which runs a driving chain 39. The chain 39 may be operatively coupled to another sprocket on a power driven device such as a. washing machine drum or a churn not shown.

The arrangement of the expansion pulleys l2 and i3 is such that when one thereof is expanded, theother thereof is contracted. This arrangement provides driving engagement betweenbut one expansion pulley and its associated belt at any given time. As an example, when .the expansion pulleys I2 and I3 are in the position shown in Figs. 1, 2, and 4, the belt 34. isin driving engagement with the expansion pulley I2 and its cooperatively-aligned pulley 28. The belt 35, being entirely disengaged from the flanges of the expansion pulley l3, will not be driven thereby. With respect to Fig. 3, a clockwiserotation of the primary shaft will impart a clockwise rotation. to thepulley Y28 and, through the reversingv ears 36 and 31, a counter-clockwise rotation to the output shaft 3|.

Axial movements of the hub 23 from the left to. the right, with respect to Figs. 1, 2and 4, will expand the pulley l2 and contract the pulley I3. The belt 34 will thus be freed from engagement with the flanges l4 and I6, and the belt 35 will be frictionally engaged and driven by the flanges and I1. Thus, with respect to Fig. 3, clockwise rotation of the primary shaft 3 will causetheoutput shaft 3| to be also rotated in a clockwise direction while the belt 34 idles over the expanded pulley l2 in a reverse direction.

I provide means for shifting the movable portions. of the expansion pulleys l2 and I3, in the nature of a shifter fork 43 comprising a shifter arm 4| and a shifter lever 42, each having its lower end fast on a rock shaft 43, which is journalled in bearings 44 secured to the base I A pair of rollers 45 are journalled, one to the upper end of the shifter arm 4| and one to the intermediate portion of the shifter lever 42. The rollers 45 are disposed at a level with the axis of the primary shaft 3 and at diametrically opposite sides thereof within the channel 24. A block 46 is journalled to the upper end of the shifter lever 42 and is provided with a transversely extending hole 41 in which is slidably mounted. a pitman arm 48.

Mounted fast on the primary shaft 3 within the gear housing 6 is a worm 49 which has meshing engagement with a worm gear 50 fast on a. shaft 5| journalled in the gear housing 6. The shaft 5| extends outwardly of the gear housingv 6 and has fast on its outer end a crank. in the nature of a disc 52 and a crank pin 53 secured thereto. The pitman arm 48 is provided with a bifurcated end 54 that fits over the crank pin 53 and may be rotatably secured thereto by means of a bolt or the like 55. A pair of coil compression springs 56 encompass the pitman arm 48, one on each side of the block 46, and impart opposing normally equal bias thereto. The extent of bias produced by the springs 56 is determined by adjustment of washer-equipped adjusting nuts 51, which are threaded on the pitman arm 48. It will be noted that the longitudinal travel of the pitman arm 48 is substantially greater than the amount necessary to shift the hub 23 from one extreme position to the other. When the limit of... travel of the shifter lever 42 is reached in either direction, added motion of the pitman arm 48 results in compression of one or the other of the springs 56. The springs 56 serve to cushion the engagement of the belt by the flanges of the expansion pulleys and prevent the belts from being pressed too tightly betweenthe pulley flanges when engaged thereby.

Rotation of the. primary shaft 3 will rotate the disc 52 and cause reciprocation of the pitman arm 48. This reciprocation is transferred tothe movable members of the expansion pulleys l2 and.

I3, so that the endless belts 34 and .35 are alternately frictionally engaged by their respective expansion pulleys l2 and. 3. This alternate engagement results in a periodic reversal of rotation ofthe output shaft 3| and mechanismdriven thereby- For driving the output shaft 3| constantly in a selected direction, I provide a pair of stationary holding pins 58 on a bracket 59 secured .,to the gear housing 6. The pins. 58 are. spaced apart substantially equalto the diametrical travel of the crank pin 53 andsimilar in construction. to said crank pin. The bifurcated end 54 of the pitman arm. .48 may beeasily and quickly removed.

from the crank pin 53 by merely removing the bolt and thereafter secured to either of. the holding pins 58 according to the direction. of.rotation. desired in the output shaft 3|. when the pitman arm 48 is disposed as shownby dotted lines in Fig.. 2, the belt 34 is continuously engagedv by the expansion pulley l2 for travel.

in one direction, and the belt 35 continuously idles over the expansion pulley l3 in a reverse direction.

In the modified form of my invention illustrated.

inFigs. 5 to 8, inclusive, parts identical to those shown in Figs. 1 to 4 inclusive, bear the same numbers with prime marks added. In this struc.

ture, I provide, in addition to the primary shaft 3, a counter shaft 68 journalled in a bearing bracket 8| on a gear housing 6'. A pair of intermeshinggears 62.and 63 are fast on the primary shaft 3' and counter shaft 60, respectively, whereby to continuously rotate the counter shaft 60 in a reverse direction with respect to the direction of rotation of the primary shaft 3'. The counter shaft 60 is held against axial movements by substantial abutting engagement of the gear 63 with one end of the bearing bracket 6| and a collar E l-secured to the counter shaft 68 adjacent the other end-of the bracket 6|.

A pair of expansion pulleys 65 and BB'are respectively carried by the shafts 3 and 60 and. as shown", are in axially spaced radially overlapping relation, one' with respect to the other. The expansion pulley 65 comprises an axially stationary pulley flange I5 and an axially movable pulley flange .67. Astop collar 68, secured'to the'pri- Hence,

assaosa 69. A stop collar secured to the counter shaft 60 limits axial movement of the pulley flange 69 in one direction.

A power output shaft II is journalled in spaced relation to the shafts 3' and 60 in a bearing" bracket 12 secured to the base I. Pulleys 28' and 29 are secured to the shaft 1| adjacent either end of the bearing bracket I2 and in cooperative alignment with the expansion pulleys 66 and 65* respectively. A driving sprocket 3B is secured to the output shaft H, and a driving chain 35' is adapted to drive a power operated device, not

shown. The endless belt 34' runs over the ex;- pansion pulley 66 and the output pulley 28; and

the belt 35' run over the expansion pulley 65 and the output pulley 29'.

61 and 69 comprises a shifter fork, indicated in its entirety by the numeral 13, a pitman arm 48' connected thereto, and to a crank pin 53' on' a disc 52', which is driven from the primary shaft- 3 through a worm 49 and a worm gear 50'. The shifter fork 13 includes shifter arms 14 and .15- and a shifter lever 16, all of which are secured fast at their lower end to a rock shaft 11 journalled in bearings 44' bolted or otherwise secured to the base I. Shifter rollers 45 are journalled to the upper ends of the shifter arms 14 and '15 and to the intermediate portion of the shifter lever lB and are positioned to engage the adjacent pulley flanges 61 and 69. The arms and lever 16 are so positioned that the rollers '45 thereon move only against the pulley flange '69 and 61, respectively; whereas th roller-equipped arm is so positioned that the roller 45' thereon maymove to engage the radially overlapping por tions of the pulley flanges 61 and 69. i

It is important to note that the pulley flanges l3 and l4, l6 and l1, l4 and I5 and 61 and 69 have opposed sloping belt-engaging surfaces A adjacent the peripheral portions thereof and other opposed sloping surfaces B extending radially inwardly from the surfaces A to the bottoms of the grooves formed by the flanges and their hubs. The opposing surfaces A form an angle which corresponds to the angle of a V- belt running therebetween, whereas the angle between opposed surfaces B i more acute. In fact, the angles formed by the opposed surfaces A measures substantially 30 of circular arc, and I provide an included angle between the opposed surfaces 3 of approximately of circular arc. This smaller angle permits the cooperating flanges to approach one another to a greater extent than would be possible if the surfaces A extended to the bottom of the groove, and obviates the'ne-' cessity of providing radial slots in opposing flanges for the purpose of intermeshing the same. Further, the reduced angle provide a wider separation at the bottom of the V groove with less axial separating movement of opposing flanges,

The angularity of opposing surfaces B is -.-sufflcient to urge the cooperating belts radi=ally'..outwardly toward ,the surfaces A when the flanges are moved to'a'pulley-contracted position'l and during rotation thereof.

It "is apparent from the foregoing that the expansion pulleys and endless belts cooperate to provide combining clutching and power transfer elements and eliminate any need for a separate driving or reversing clutch.

. 1 20 Means for shifting the movable pulley flanges- My invention has been thoroughly tested and found to be entirely satisfactory in accomplishing the desired results. 1

What I claim is:

1. Power transmission mechanism comprising a pair of expansion pulleys, a pair of other pulleys in spaced co-operatively aligned relation to said expansion pulleys, intermeshing reversing gears driving one of the pulleys of one of said pairs in a reverse direction to the second pulley of'the same pair, a pair of endless belts, one each running over one of said expansion pulleys and its co-operatively aligned other pulley, means for manipulating said expansion pulleys to selectively and singularly bring the same into frictional driving engagement with their respective belts, said last named means including means for cushioning and timing the operation of the expansion pulleys in relation to each other and in their driving of the belts.

2. A power transmission mechanism comprising a primary shaft, bearings journalling said shaft, a second shaft and a power take-off shaft journalled in spaced relation to each other and to said primary shaft, intermeshing reversing gears on said second shaft and power take-off shaft, an axially spaced pair of expansible pulleys mounted on said primary shaft and each having a relatively fixed member and an axially movable member, a pair of other pulleys one each on said second shaft and said power take-off shaft in cooperative alignment with one each of said expansible pulleys, a pair of endless belts each running over a different expansion pulley and its co-operatively aligned other pulley, and means for shifting said movable members to alternatively bring said expansible pulleys into frictional driving engagement with their respective belts, said means for shifting said movable members including a rock shaft, a shifter fork on said rock shaft and operatively associated with said movable members, a crank, a worm gear connection between said crank and said primary shaft, and a pitman arm pivoted at one end to said crank and adjacent its other end to said shifter fork.

'3. A power transmission mechanism comprising a primary shaft, bearings journalling said shaft, an expansion pulley on said shaft, a countershaft joiirnaled in spaced relation to said primary shaft, intermeshing reversing gears on said shafts, an expansion pulley on said countershaft, a power transmission pulley journalled in spaced relation to said primary shaft and co-operatively aligned with the expansion pulley thereon, a second power transmission pulley journalled in spaced relation to said countershafts and co-operatively aligned with the expansion pulley thereon, and a pair of endless belts each running over a different expansion pulley and its co-operatively aligned power transmission pulley.

4. A power transmission mechanism compris-' ing a primary shaft, bearings journalling said shaft, an expansion pulley on said shaft, a countershaft journalled in spaced relation to said primary shaft, intermeshing reversing gears on said shafts, an expansion pulley on said countershaft, a power take-off shaft journalled in spaced rela tion to said primary shaft and said countershaft, a pair of pulleys rigid on said power take-off shaft and each co-operatively aligned with a different of said expansion pulleys, and endless belts each running over an expansion pulley and a cooperatively aligned pulley on said power takeoff shaft.

. 5.. A power transmission'mechanism comprising a primary shaft, bearings journalling said shaft, an expansion pulley on said shaft, a countershaft journalled in spaced relation to said primary shaft, intermeshing reversing gears on said shafts, an: expansion pulley on said countershaft, a powertransmission pulley journalled in spaced relation to said primary shaft and co-operatively aligned with the expansion pulley thereon, a second power transmission pulley journalled in spaced relation to said countershaft and co-operatively aligned with the expansion pulley thereon, a pair of endless belts each running over a different expansionpulley and its co-operatively aligned power transmission pulley, and means for manipulating said expansion pulleys to seleotively and singularly bring the same into frictional driving engagement with their respective belts.

'6; A power transmission mechanism comprising a primary shaft, bearings journalling said shaft, an expansion pulley on said primary shaft, a countershaft journalled in spaced parallel relationto saidv primary shaft, intermeshing reversing gears on said shafts, an expansion pulley on said countershaft, said expansion pulleys being disposed in axially spaced radially overlapping arrangement one with respect to the other thereof, a power take-off shaft journalled in spaced relation to said primary shaft and said countershaft, a pair of pulleys rigid on said power takeoff shaft and each co-operatively aligned with a different of said expansion pulleys, endless belts each running over an expansion pulley and a cooperatively aligned pulley on said power take-off shaft, and means engageable with the radially overlapping portions of said expansion pulleys for manipulation thereof whereby to alternately bring the same into frictional driving engagement with their respective belts.

7. A power transmission mechanism comprising a primary shaft, bearings journalling said shaft, a countershaft journalled in spaced parallel relation to said primary shaft, intermeshing reversing gears on said shafts, a pair of expansible pulleys mounted one each on said shafts and each having a fixed member and an axially movable member, said pulleys being disposed in axially spaced radially overlapping arrangement one with respect to the other thereof and having the movable member of one thereof in opposing relation to the movable member of the other thereof, a power take-off shaft journalled in spaced relation to said primary shaft and said countershaft, a pair of pulleys rigid on said power take- 01T shaft and each co-operatively aligned with a different of said expansible pulleys, endless belts each running over an expansible pulley and a co-operatively aligned pulley on said power take-01f shaft, and shifter means interposed between the overlapping portions of said movable members for selectively and singularly moving the same into frictional driving engagement with their respective belts.

8. A power transmission mechanism comprising a primary shaft, bearings journalling said shaft; acountershaft journalled in spaced parallel relation to said primary shaftaintermeshing reversing, gears on said shafts, a pair of expansible pulleysmounted one each on said shafts andeach having a fixed member and an axially movable member, said pulleys being disposed in axially spaced radially overlapping arrangement one with respect to the other thereof and having a movable member of one thereof in opposing relation to the movable member of the other thereof, a power take-off shaft journalled in spaced relation to said primary shaft and said countershaft; a pair of pulleys rigid on said power take-01f shaft and each co-operatively aligned with a different of said expansible pulleys, endless belts each running over an expansible pulley and a co-operatively aligned pulley on said power take-off shaft, and shifter means interposed between the overlapping portions of said movable members for alternately moving the same into frictional driving engagement with their respective belts. 9. The structure defined in claim 8 in which the means for shifting said movable members includes a rock shaft, a shifter fork on said rock shaft and operatively associated with said movable members, a crank, worm gear connections between said crank and said primary shaft, andv a pitman arm pivoted at one end to said crank and adjacent its other end to said shifter fork.

10. The structure defined in claim 2 in which said relatively fixed members-and said axially movable members having opposed outwardly diverging sloping belt-engaging surfaces adjacent the peripheral portions thereof and other opposed outwardly diverging sloping surfaces radially inwardly of said first-mentioned surfaces, the outer sloping surface on each member being angularly disposed with respect to the surface radially inwardly thereof and at a greater angle.

11. The structure defined in claim 7 in which said relatively fixed members and said axially movable members have opposed sloping beltengaging surfaces adjacent the peripheral'portionsthereof and other opposed sloping surfaces radially inwardly of said first-mentioned surfaces, the outer sloping surface on each member being angularly disposed with respect to the surface radially inwardly thereof.

12. A device as set forth in claim 2-including a yieldable cushioning connection between the shifter fork and the pitman.

13. A device as set forth in claim 2 wherein the connection between the shifter fork and the pitman comprises a pitman guide member carried by the shifter fork and through which the pitman extends and moves, coiled springs surtive belt for a continuous driving in one direc-' tion.

GEORGE H. AMONSEN.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS Number Name Date 804,980 Reiss Nov. 21, 1905 2,097,559 Brownlee Nov. 2, 1937 2,175,830 Davis -Oct. 10, 1939 

